Polite Past (-았/었어요)

The past tense in polite informal speech is formed by adding -았어요 or -었어요 to the verb stem. The vowel harmony rule is the same as the present tense: if the stem's last vowel is ㅏ or ㅗ, use -았어요; otherwise, use -었어요. 하다 verbs become 했어요.

Examples: 가다 → 갔어요 (went), 먹다 → 먹었어요 (ate), 공부하다 → 공부했어요 (studied). Notice that vowel contractions occur: 가 + 았어요 → 갔어요, 오 + 았어요 → 왔어요.

The past tense is used for completed actions and past experiences. It can also express a recently discovered state: '꽃이 예뻤어요' (The flowers were pretty — I noticed). This form is essential for talking about daily activities, past events, and sharing experiences.